Editorial Type:
Article Category: Research Article
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Online Publication Date: 15 Sept 2006

A New Species of Raiamas (Teleostei: Cyprinidae) from the Lower Congo River, with a Phylogenetic Assessment of the Generic Limits of the Predatory Cyprinid Genera Opsaridium, Raiamas, and Leptocypris

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Page Range: 370 – 377
DOI: 10.1643/0045-8511(2006)2006[370:ANSORT]2.0.CO;2
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Abstract

In the course of ongoing survey work in the lower Congo River, two collections of an undescribed species of the predatory cyprinid genus Raiamas have been made; one in the Congo main channel in the vicinity of Inga, and a second in the Inkisi River, a large south bank tributary of the Congo. Discovery of this new taxon has prompted a reexamination of potentially related taxa of adjacent regions and an attempt to provide generic diagnoses for the morphologically similar cyprinid genera Leptocypris, Raiamas, and Opsaridium. Based on a series of derived features of the neurocranium, pectoral girdle, jaws, and suspensorium, anatomical diagnoses for the three cyprinid genera are provided. We reassign Opsaridium christyi to Raiamas and Raiamas weeksii to Leptocypris. These two generic reassignments and the discovery of the new Raiamas bring the number of species of Raiamas confirmed from the lower Congo River to four: R. salmolucius, R. buchholzi, R. christyi, and the new species, R. kheeli, described herein. The reassignment of Opsaridium weeksii to Leptocypris raises the number of species of Leptocypris recorded from the region to four: L. modestus, L. lujae, L. weynsii, and L. weeksii.

Copyright: 2006 by the American Society of Ichthyologists and Herpetologists
Figure 1
Figure 1

Anatomical coordinates for principal counts and measurements.

Figure 2
Figure 2

Posterior neurocranium, pectoral girdle, suspensorium, and jaws. (A) Opsaridium ubangiense AMNH 12411; (B) Raiamas salmolucius AMNH 227488; (C) Leptocypris modestus AMNH 5850.

Figure 3
Figure 3

Posterior neurocranium, pectoral girdle, suspensorium, and jaws. (A) Raiamas christyi AMNH 236349; (B) Leptocypris weeksii AMNH 236347; (C) Raiamas kheeli, new species AMNH 236354.

Figure 4
Figure 4

(A) Raiamas christyi AMNH 236349; (B) Raiamas buchholzi AMNH 232380; (C) Raiamas salmolucius AMNH 227488; (D) Leptocypris weeksii AMNH 236347.

Figure 5
Figure 5

Raiamas kheeli, new species AMNH 236352, holotype, 95.8 mm SL, Democratic Republic of Congo, small channel adjacent to main channel rapid, just below Inga intake canal.

Figure 6
Figure 6

Coloration (immediately after capture). (A) Raiamas kheeli, new species; (B) Raiamas christyi; (C) Raiamas buchholzi; (D) Leptocypris weeksii.

Figure 7
Figure 7

Map of the lower Congo River drainage network with collection localities of Raiamas kheeli, new species indicated with black circles.

Contributor Notes

(MLJS, RCS) Department of Ichthyology, Division of Vertebrate Zoology, American Museum of Natural History, 79th Street at Central Park West, New York, New York 10024; and (UKS) Zoological State Collection Munich, Department of Ichthyology, Münchhausenstrasse 21, D-81247 München, Germany. E-mail: (MLJS) mljs@amnh.org. Send reprint requests to MLJS.

Received: 14 Nov 2005
Accepted: 09 May 2006
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